A coating film device

Abstract

The utility model relates to the technical field of coating equipment provides a kind of coating device, comprising: seat body, first vacuum channel, second vacuum channel, liquid injection mechanism and liquid discharge mechanism;The seat body has chamber;The chamber has the placement site for placing ceramic tube in;The liquid injection mechanism and liquid discharge mechanism are communicated with the chamber respectively;One end of the first vacuum channel is communicated with the chamber, and the other end of the first vacuum channel is used to be communicated with first external evacuator;One end of the second vacuum channel is used to be communicated with the internal space of the ceramic tube, and the other end of the second vacuum channel is used to be communicated with second external evacuator.

Description

Technical Field

[0001] This utility model belongs to the field of coating equipment technology, and more specifically, relates to a coating device. Background Technology

[0002] Dip coating is a coating process in which a substrate is immersed in a suspension (containing a coating agent, i.e., a coating solution). The suspension is coated onto the substrate surface through capillary and adhesive forces, followed by drying and sintering to form a film. This method is widely used in industrial production. Compared to other coating technologies such as spraying and sol-gel methods, dip coating requires simpler equipment and has lower costs. The process is simple, the coating solution can be reused, reducing resource waste and environmental pollution. Dip coating is applicable to substrates of various shapes and film materials, offering great flexibility and wide applicability. The quality of the film produced using dip coating is closely related to the viscosity of the coating solution, immersion time, extraction rate, and substrate structure. Currently, dip coating relies heavily on manual operation, resulting in low actual production efficiency and failing to meet the demands of mass production.

[0003] Ceramic support tubes, which play a crucial role in separation and filtration, are porous materials composed of interconnected pores. They possess excellent properties such as high temperature resistance, corrosion resistance, organic solvent resistance, and high mechanical strength, and are widely used in building materials, chemical, and food industries. In industrial production, the most common coating process for ceramic tube surfaces is dip coating. Although dip coating has many advantages in industrial applications, the dip coating process using porous ceramic tubes as substrates still has the following main problems: (1) Due to the porous structure of ceramic tubes, in general dip coating process, particles in the solution penetrate through the surface pores, compress the gas inside the tube, and have an outward diffusion force, causing the gas inside the tube to escape from the coating surface, generating bubbles and forming defects such as pits or pinholes; (2) During the dip coating process, the coating liquid fails to expel the gas in the solution, causing the gas to escape from the coating during the drying stage, generating bubbles and forming defects such as pits or pinholes; (3) The coating adheres to the surface pores of the ceramic tube through capillary action, and the degree of penetration varies depending on the surface pores, and the coating thickness is not uniform, which makes it easy for the solvent in the coating to not dry completely during the drying process, easily causing uneven shrinkage, resulting in cracks or deformation. Utility Model Content

[0004] The purpose of this invention is to provide a coating device to solve the technical problem in the prior art where gas inside a ceramic tube permeates outward from its porous surface, affecting the coating on the ceramic tube surface.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a coating device is provided, comprising: a base, a first vacuum channel, a second vacuum channel, a liquid injection mechanism, and a liquid drainage mechanism; the base has a chamber; the chamber has a placement position for placing a ceramic tube; the liquid injection mechanism and the liquid drainage mechanism are respectively connected to the chamber; One end of the first vacuum channel is connected to the chamber, and the other end of the first vacuum channel is used to connect to the first external vacuum pump. One end of the second vacuum channel is used to communicate with the internal space of the ceramic tube, and the other end of the second vacuum channel is used to communicate with the second external vacuum pump.

[0006] Furthermore, it also includes: a first external vacuum pump; one end of the first vacuum pumping channel is connected to the chamber, and the other end of the first vacuum pumping channel is connected to the first external vacuum pump.

[0007] Furthermore, it also includes: a second external vacuum pump; one end of the second vacuum channel is used to communicate with the internal space of the ceramic tube, and the other end of the second vacuum channel is connected to the second external vacuum pump.

[0008] Furthermore, it also includes: a first sealing mechanism and a second sealing mechanism; the base is a hollow cylinder; the two ends of the cylinder have a first opening and a second opening respectively; the first opening is sealed by the first sealing mechanism; the first sealing mechanism has an extension hole for one end of the ceramic tube to extend out of the outside of the base, and one end of the second vacuum channel is used to communicate with the internal space of the ceramic tube located outside the base; the second opening is sealed by the second sealing mechanism.

[0009] Furthermore, the first sealing mechanism includes: a first sealing plate, a first sealing ring, and a fixing mechanism; the first sealing plate covers and seals the first opening, and the fixing mechanism installs the first sealing plate on the base; the first sealing plate has the protrusion hole; the first sealing ring is disposed in the protrusion hole; the first sealing ring is used to seal the gap between the ceramic tube and the inner wall of the protrusion hole.

[0010] Further, the fixing mechanism includes: a front cover plate, an annular sealing sheet, a second sealing ring, and a first fastener; the annular sealing sheet is laid on the edge of the first sealing plate and the edge of the first opening; the front cover plate covers the first sealing plate, and the front cover plate is fixed to the base by the first fastener; the annular sealing sheet is sandwiched between the edges of the front cover plate and the first sealing plate, and between the edges of the front cover plate and the first opening; the front cover plate has a first positioning hole communicating with the protruding hole; the second sealing ring is disposed in the first positioning hole; the second sealing ring is used to seal the gap between the ceramic tube and the inner wall of the first positioning hole.

[0011] Furthermore, the second sealing mechanism includes: a second sealing plate, a sealing plate, a rear cover plate, and a second fastener; the second sealing plate covers and seals the second opening; the sealing plate is laid on the edge of the second sealing plate and the second opening; the rear cover plate covers the second sealing plate, and the rear cover plate is fixed to the base by the second fastener; the sealing plate is clamped between the edge of the second opening and the rear cover plate.

[0012] Furthermore, it also includes: a third sealing ring; a second positioning hole is provided on the second sealing plate for the other end of the ceramic tube to be inserted; the third sealing ring is disposed in the second positioning hole; the third sealing ring is used to seal the gap between the ceramic tube and the inner wall of the second positioning hole.

[0013] Furthermore, there are multiple first positioning holes, multiple protruding holes, and multiple second positioning holes; the number of multiple first positioning holes, multiple protruding holes, and multiple second positioning holes are respectively one-to-one.

[0014] Furthermore, it also includes: a pressure gauge; the pressure gauge is used to detect the air pressure in the chamber; the pressure gauge is disposed on the base.

[0015] The advantages of the coating device provided by this utility model are as follows: Compared with the prior art, the coating device provided by this utility model has a chamber in the base, and a placement position in the chamber, where the ceramic tube can be placed; one end of the first vacuum channel is connected to the chamber, and the other end of the first vacuum channel can be connected to the first external vacuum pump; the first external vacuum pump can evacuate the chamber through the first vacuum channel; that is, the chamber outside the ceramic tube can be evacuated by the first vacuum pump; the liquid injection mechanism can inject coating liquid into the chamber, and the ceramic tube in the chamber can be immersed in the coating liquid. The coating can cover the ceramic tube; one end of the second vacuum channel is connected to the internal space of the ceramic tube, and the other end of the second vacuum channel is connected to the second external vacuum pump; the second external vacuum pump can evacuate the internal space of the ceramic tube through the second vacuum channel; that is, the internal space of the ceramic tube can be evacuated by the second vacuum pump; since both the internal and external spaces of the ceramic tube are evacuated, the gas inside the ceramic tube is not easy to escape and affect the coating effect on the surface of the ceramic tube; after the ceramic tube has been immersed in the coating liquid for the required time, the coating liquid in the chamber can be discharged through the drainage mechanism. Attached Figure Description

[0016] Figure 1 A three-dimensional schematic diagram of the coating device provided in the embodiment of this utility model. Figure 1 (The front cover and rear cover are separate.) Figure 2 A schematic diagram of the coating device provided in an embodiment of the present invention (the front cover plate and the rear cover plate are separated). Figure 3 A front view of the coating device provided in an embodiment of the present utility model (the front cover plate and the rear cover plate are separate). Figure 4 for Figure 3 Sectional view of AA; Figure 5 for Figure 4 Enlarged view at point C; Figure 6 for Figure 4 Enlarged view at point D; Figure 7 for Figure 3 BB section view; Figure 8 A bottom view of the coating device provided in an embodiment of the present utility model (the front cover plate and the rear cover plate are separated). Figure 9 A perspective view of the coating device provided in an embodiment of the present utility model (the front cover plate is hidden; the rear cover plate is separate). Figure 10 A three-dimensional schematic diagram of the coating device provided in the embodiment of this utility model. Figure 2 (The front cover and rear cover are separate.) Figure 11 A perspective view of the coating device provided in an embodiment of the present utility model (the rear cover is hidden; the front cover is separate). Figure 12 A perspective view of the coating device provided in the embodiment of this utility model (the rear cover and sealing plate are hidden, and the front cover is separate).

[0017] The following are the labeling elements in the figure: 1-Base; 11-Cavity; 111-First opening; 112-Second opening; 113-Placement position; 21-First vacuum channel; 22-Second vacuum channel; 31-Injection mechanism; 32-Drainage mechanism; 4-First sealing mechanism; 41-First sealing plate; 411-Extend hole; 42-First sealing ring; 43-Fixing mechanism; 431-Front cover plate; 4311-First positioning hole; 432-Annular sealing sheet; 433-Second sealing ring; 434-First fastener; 5-Second sealing mechanism; 51-Second sealing plate; 511-Second positioning hole; 52-Sealing plate; 53-Rear cover plate; 54-Second fastener; 55-Third sealing ring; 61-Pressure gauge; 62-Ceramic tube; 63-Pipe clamp; 64-Base. Detailed Implementation

[0018] It should be noted that the specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0019] It should be noted that, in the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Here, A and B can be singular or plural, respectively.

[0020] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as "connected to" or "attached to" another component, it can be directly connected to or indirectly connected to that other component. When a component is referred to as "fixed to" or "set on" another component, it can be directly on or indirectly on that other component.

[0021] It should be noted that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0022] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0023] It should be noted that the term "multiple" means two or more, unless otherwise explicitly specified.

[0024] Please refer to the following: Figures 1 to 12 The coating device provided by this utility model will now be described. The coating device includes: a base 1, a first vacuum channel 21, a second vacuum channel 22, a liquid injection mechanism 31, and a liquid drainage mechanism 32; the base 1 has a chamber 11; the chamber 11 has a placement position 113 for placing a ceramic tube 62; the liquid injection mechanism 31 and the liquid drainage mechanism 32 are respectively connected to the chamber 11; one end of the first vacuum channel 21 is connected to the chamber 11, and the other end of the first vacuum channel 21 is connected to a first external vacuum pump; one end of the second vacuum channel 22 is connected to the internal space of the ceramic tube 62, and the other end of the second vacuum channel 22 is connected to a second external vacuum pump.

[0025] Thus, the base 1 has a chamber 11, and the chamber 11 has a placement position 113, on which the ceramic tube 62 can be placed; one end of the first vacuum channel 21 is connected to the chamber 11, and the other end of the first vacuum channel 21 can be connected to the first external vacuum pump; the first external vacuum pump can evacuate the chamber 11 through the first vacuum channel 21; that is, the chamber 11 outside the ceramic tube 62 can be evacuated by the first vacuum pump; the liquid injection mechanism 31 can inject coating liquid into the chamber 11, and the ceramic tube 62 in the chamber 11 can be immersed in the coating liquid, and the coating liquid can cover the ceramic tube 62; the first One end of the second vacuum channel 22 is connected to the internal space of the ceramic tube 62, and the other end of the second vacuum channel 22 is connected to the second external vacuum pump. The second external vacuum pump can evacuate the internal space of the ceramic tube 62 through the second vacuum channel 22. That is, the internal space of the ceramic tube 62 can be evacuated by the second vacuum pump. Since both the internal and external spaces of the ceramic tube 62 are evacuated, the gas inside the ceramic tube 62 is not easy to escape and affect the coating effect on the surface of the ceramic tube 62. After the ceramic tube 62 has been immersed in the coating liquid for the required time, the coating liquid in the chamber 11 can be discharged through the draining mechanism 32.

[0026] In one embodiment, the placement position 113 is any one of a space, groove, or recess within the chamber 11.

[0027] In one embodiment, the first vacuum channel 21 is a pipe. In another embodiment, the first vacuum channel 21 is a metal pipe or a flexible hose.

[0028] In one embodiment, the second vacuum channel 22 is a pipe. In another embodiment, the second vacuum channel 22 is a metal pipe or a flexible hose.

[0029] In one embodiment, the internal space of the ceramic tube 62 is: the cavity inside the ceramic tube 62.

[0030] In one embodiment, a first vacuum channel 21 is disposed on the base 1. In another embodiment, the first vacuum channel 21 communicates with the top of the chamber 11.

[0031] In one embodiment, the second vacuum channel 22 is disposed on the base 1.

[0032] In one embodiment, the first external vacuum pump is a vacuum pump.

[0033] In one embodiment, the second external vacuum pump is a vacuum pump.

[0034] In one embodiment, the base 1 is disposed on the base 64. In one embodiment, there are two bases 64. In one embodiment, the two bases 64 are disposed at a distance from each other.

[0035] In one embodiment, the liquid injection mechanism 31 includes: an inlet pipe, a pump body, and a liquid reservoir; the liquid reservoir is connected to the chamber 11 via the pump body and the inlet pipe; liquid in the liquid reservoir can be pumped into the chamber 11 by the pump body. In one embodiment, the pump body is a peristaltic pump. In one embodiment, the liquid reservoir is a tank. In one embodiment, the inlet pipe is connected to the top of the chamber 11.

[0036] In one embodiment, the drainage mechanism 32 includes a drainage pipe and a valve; the valve is disposed on the drainage pipe, and one end of the drainage pipe is connected to the chamber 11. In one embodiment, the drainage pipe is connected to the bottom of the chamber 11. In one embodiment, a pump is disposed on the drainage pipe.

[0037] Further, please refer to Figures 1 to 12 As a specific embodiment of the coating device provided by this utility model, it further includes: a first external vacuum pump; one end of the first vacuum channel 21 is connected to the chamber 11, and the other end of the first vacuum channel 21 is connected to the first external vacuum pump. In this way, the first external vacuum pump can evacuate the chamber 11.

[0038] Further, please refer to Figures 1 to 12 As a specific embodiment of the coating device provided by this utility model, it further includes: a second external vacuum pump; one end of the second vacuum channel 22 is used to communicate with the internal space of the ceramic tube 62, and the other end of the second vacuum channel 22 is connected to the second external vacuum pump. In this way, the second external vacuum pump can evacuate the internal space of the ceramic tube 62 placed in the chamber 11.

[0039] In one embodiment, the second vacuum channel 22 is fitted onto the ceramic tube 62 via a pipe clamp 63.

[0040] Further, please refer to Figures 1 to 12As a specific embodiment of the coating device provided by this utility model, it further includes: a first sealing mechanism 4 and a second sealing mechanism 5; the base 1 is a hollow cylinder; the two ends of the cylinder have a first opening 111 and a second opening 112 respectively; the first opening 111 is sealed by the first sealing mechanism 4; the first sealing mechanism 4 has an extension hole 411 for one end of the ceramic tube 62 to extend out of the outside of the base 1, and one end of the second vacuum channel 22 is used to communicate with the internal space of the ceramic tube 62 located outside the base 1; the second opening 112 is sealed by the second sealing mechanism 5. Thus, the ceramic tube 62 can be placed into the chamber 11 through the first opening 111 or the second opening 112; the first sealing mechanism 4 can seal the first opening 111, and the second sealing mechanism 5 can seal the second opening 112; one end of the ceramic tube 62 can pass through the extension hole 411 and extend to the outside of the chamber 11; the second vacuum channel 22 can communicate with the internal space of the ceramic tube 62 outside the chamber 11, so that the second vacuum channel 22 can evacuate the internal space of the ceramic tube 62.

[0041] Further, please refer to Figures 1 to 12 As a specific embodiment of the coating device provided by this utility model, the first sealing mechanism 4 includes: a first sealing plate 41, a first sealing ring 42, and a fixing mechanism 43; the first sealing plate 41 covers and seals the first opening 111, and the fixing mechanism 43 installs the first sealing plate 41 on the base 1; the first sealing plate 41 has an extension hole 411; the first sealing ring 42 is disposed in the extension hole 411; the first sealing ring 42 is used to seal the gap between the ceramic tube 62 and the inner wall of the extension hole 411. Thus, the first sealing plate 41 can seal the first opening 111, and the extension hole 411 on the first sealing plate 41 allows one end of the ceramic tube 62 to extend out of the outside of the chamber 11 through the extension hole 411; the first sealing ring 42 in the extension hole 411 can seal the gap between the ceramic tube 62 and the inner wall of the extension hole 411.

[0042] Further, please refer to Figures 1 to 12As a specific embodiment of the coating device provided by this utility model, the fixing mechanism 43 includes: a front cover plate 431, an annular sealing sheet 432, a second sealing ring 433, and a first fastener 434; the annular sealing sheet 432 is laid on the edge of the first sealing plate 41 and the edge of the first opening 111; the front cover plate 431 covers the first sealing plate 41, and the front cover plate 431 is fixed to the base 1 by the first fastener 434; the annular sealing sheet 432 is clamped between the edge of the front cover plate 431 and the edge of the first sealing plate 41, and the annular sealing sheet 432 is clamped between the edge of the front cover plate 431 and the edge of the first opening 111; a first positioning hole 4311 communicating with the protrusion hole 411 is opened on the front cover plate 431; the second sealing ring 433 is disposed in the first positioning hole 4311; the second sealing ring 433 is used to seal the gap between the ceramic tube 62 and the inner wall of the first positioning hole 4311. Thus, the annular sealing sheet 432 can seal the gap between the edge of the first opening 111 and the edge of the first sealing plate 41; the first fastener 434 can lock the front cover plate 431 and the seat 1; the annular sealing sheet 432 is clamped between the front cover plate 431 and the edge of the first opening 111, and the annular sealing sheet 432 is clamped between the front cover plate 431 and the edge of the first sealing plate 41, improving the sealing effect of the annular sealing sheet 432; the ceramic tube 62 can be positioned by being inserted into the first positioning hole 4311; the second sealing ring 433 can seal the gap between the ceramic tube 62 and the first positioning hole 4311.

[0043] In one embodiment, the first fastener 434 is a first screw.

[0044] Further, please refer to Figures 1 to 12 As a specific embodiment of the coating device provided by this utility model, the second sealing mechanism 5 includes: a second sealing plate 51, a sealing plate 52, a rear cover plate 53, and a second fastener 54; the second sealing plate 51 covers and seals the second opening 112; the sealing plate 52 is laid on the edges of the second sealing plate 51 and the second opening 112; the rear cover plate 53 covers the second sealing plate 51, and the rear cover plate 53 is fixed to the base 1 by the second fastener 54; the sealing plate 52 is clamped between the edge of the second opening 112 and the rear cover plate 53. Thus, the second sealing plate 51 can seal the second opening 112; the sealing plate 52 can seal the second opening 112; the rear cover plate 53 is fixed to the base 1 by the second fastener 54, and the sealing plate 52 is clamped more firmly between the rear cover plate 53 and the edge of the second opening 112.

[0045] In one embodiment, the second fastener 54 is a second screw.

[0046] Further, please refer to Figures 1 to 12As a specific embodiment of the coating device provided by this utility model, it further includes: a third sealing ring 55; a second positioning hole 511 for inserting the other end of the ceramic tube 62 on the second sealing plate 51; the third sealing ring 55 is disposed in the second positioning hole 511; the third sealing ring 55 is used to seal the gap between the ceramic tube 62 and the inner wall of the second positioning hole 511. Thus, the ceramic tube 62 can be positioned by being inserted into the second positioning hole 511; the third sealing ring 55 can seal the gap between the ceramic tube 62 and the second positioning hole 511.

[0047] Further, please refer to Figures 1 to 12 In one specific embodiment of the coating device provided by this utility model, there are multiple first positioning holes 4311, multiple protruding holes 411, and multiple second positioning holes 511; the number of multiple first positioning holes 4311, multiple protruding holes 411, and multiple second positioning holes 511 are respectively one-to-one. In this way, the multiple first positioning holes 4311, multiple protruding holes 411, and multiple second positioning holes 511 can respectively cooperate with the ceramic tube 62.

[0048] Further, please refer to Figures 1 to 12 As a specific embodiment of the coating device provided by this utility model, it further includes: a pressure gauge 61; the pressure gauge 61 is used to detect the air pressure inside the chamber 11; the pressure gauge 61 is installed on the base 1. In this way, the user can view the air pressure status inside the chamber 11 through the pressure gauge 61.

[0049] In one embodiment, the ceramic tube 62 is ultrasonically cleaned in acid for a period of time, then ultrasonically cleaned again in water for 60 minutes, and then placed in a 90°C oven for drying for 8 hours. The pretreated ceramic tube 62 is fixed in the chamber 11, the chamber 11 is sealed, and all inlet and outlet valves and exhaust valves are closed. The valve of the first vacuum channel 21 and the first external vacuum pump above the device are opened to evacuate the air in the chamber 11; the valve of the inlet pipe is opened, and the coating liquid is injected into the chamber 11 through a peristaltic pump until the ceramic tube 62 is submerged, and the valve of the coating inlet pipe is closed; the second external vacuum pump connected to the ceramic tube 62 is opened to evacuate the gas in the ceramic tube 62, and the coating film is formed on the surface of the ceramic tube 62 under negative pressure; after the ceramic tube 62 is immersed for 60 seconds, the valve of the drain pipe is opened, and the coating liquid is extracted by the connected water pump; the chamber 11 is opened, the ceramic tube 62 is taken out and dried at 80°C for 10 hours. The dried ceramic tube 62 was then taken out and placed in a sintering furnace, where it was sintered at 1200℃ for 12 hours to prepare a ceramic tube 62 with a surface coating.

[0050] In one embodiment, a coating method for a ceramic tube 62 includes the following steps: (1) Pretreatment of ceramic tube 62: Place ceramic tube 62 in an ultrasonic bath for acid washing and water washing, take it out and dry it to remove oil and other impurities.

[0051] (2) Preparation of coating liquid: Select alumina micro powder, binder, dispersant, defoamer, etc. and mix them evenly by ball milling to obtain coating liquid.

[0052] (3) Install the coating device, fix the ceramic tube 62 after the pretreatment in step (1) in the chamber 11, seal the chamber 11, and close the inlet and outlet valves and the air extraction valve.

[0053] (4) Start the coating process, open the valve of the first vacuum channel 21 and the first external vacuum pump to gradually exhaust the air in the chamber 11 to a certain vacuum level; open the valve of the liquid inlet pipe and inject the coating liquid into the chamber 11 through the peristaltic pump until the ceramic tube 62 is submerged, and close the valve of the liquid inlet pipe; open the second external vacuum pump connected to the ceramic tube 62 to evacuate the gas in the ceramic tube 62 and promote the formation of the coating film on the surface of the ceramic tube 62 under negative pressure; after the ceramic tube 62 is immersed for a certain period of time, end the coating process, open the drain pipe and discharge the coating liquid through the connected water pump; open the chamber 11 and take out the ceramic tube 62.

[0054] (5) Dry the ceramic tube 62 after coating in step (4).

[0055] (6) The ceramic tube 62 obtained in step (5) is sintered at high temperature to prepare a ceramic tube 62 product with a film layer.

[0056] In one embodiment, the ultrasonic cleaning time of the ceramic tube 62 in step (1) is 30~120 min; the drying temperature is 80~110℃ and the drying time is 5~10 h.

[0057] In one embodiment, the alumina micro powder in step (2) has a particle size range of 1~5μm and an alumina solid content of 8~25%; the dispersant is one or more of polyacrylic acid, polyacryl alcohol, and polypyrrolidone, with a dispersant solid content of 5~15%; and the defoamer is one of organosilicon, paraffin, and polyether defoamers, with a defoamer content of 0.1~0.5%.

[0058] In one embodiment, the coating device in step (3) uses a first external vacuum pump connected to the first vacuum channel 21 to evacuate the chamber 11. The pressure gauge 61 can monitor the vacuum level inside the chamber 11 and promptly feed back to the vacuum pump to adjust the vacuum level inside the chamber 11. The coating liquid is injected through the peristaltic pump connected to the liquid inlet pipe until the ceramic tube 62 is submerged. When the coating is finished, the coating liquid is discharged through the water pump connected to the liquid outlet pipe, and the ceramic tube 62 is removed. The cleaning liquid is injected through the peristaltic pump connected to the liquid inlet pipe to clean the chamber 11. After cleaning, the liquid is pumped out through the water pump connected to the liquid outlet pipe.

[0059] In one embodiment, the immersion coating time in step (4) is 30~90s.

[0060] In one embodiment, the drying temperature in step (5) is 60~100℃ and the heat preservation time is 2~6h.

[0061] In one embodiment, the sintering temperature in step (6) is 1100~1300℃ and the holding time is 2~6h.

[0062] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A coating apparatus, characterized in that, include: The device comprises a base, a first vacuum channel, a second vacuum channel, a liquid injection mechanism, and a liquid drainage mechanism; the base has a chamber; the chamber has a placement position for placing a ceramic tube; the liquid injection mechanism and the liquid drainage mechanism are respectively connected to the chamber; One end of the first vacuum channel is connected to the chamber, and the other end of the first vacuum channel is used to connect to the first external vacuum pump. One end of the second vacuum channel is used to communicate with the internal space of the ceramic tube, and the other end of the second vacuum channel is used to communicate with the second external vacuum pump.

2. The coating apparatus as described in claim 1, characterized in that, Also includes: First external vacuum pump; One end of the first vacuum channel is connected to the chamber, and the other end of the first vacuum channel is connected to the first external vacuum pump.

3. The coating apparatus as described in claim 1, characterized in that, Also includes: Second external vacuum pump; One end of the second vacuum channel is used to communicate with the internal space of the ceramic tube, and the other end of the second vacuum channel is used to communicate with the second external vacuum pump.

4. The coating apparatus as claimed in claim 1, characterized in that, Also includes: First sealing mechanism and second sealing mechanism; the base is a hollow cylinder; the two ends of the cylinder have a first opening and a second opening respectively; The first opening is sealed by the first sealing mechanism; the first sealing mechanism has an extension hole for one end of the ceramic tube to extend out of the outside of the base body, and one end of the second vacuum channel is used to communicate with the internal space of the ceramic tube located outside the base body; the second opening is sealed by the second sealing mechanism.

5. The coating apparatus as described in claim 4, characterized in that, The first sealing mechanism includes: a first sealing plate, a first sealing ring, and a fixing mechanism; the first sealing plate covers and seals the first opening, and the fixing mechanism installs the first sealing plate on the base; the first sealing plate has the protrusion hole; the first sealing ring is disposed in the protrusion hole; the first sealing ring is used to seal the gap between the ceramic tube and the inner wall of the protrusion hole.

6. The coating apparatus as described in claim 5, characterized in that, The fixing mechanism includes: a front cover plate, an annular sealing sheet, a second sealing ring, and a first fastener; the annular sealing sheet is laid on the edge of the first sealing plate and the edge of the first opening; the front cover plate covers the first sealing plate and is fixed to the base by the first fastener; the annular sealing sheet is sandwiched between the edges of the front cover plate and the first sealing plate, and between the edges of the front cover plate and the first opening; a first positioning hole communicating with the protruding hole is provided on the front cover plate; the second sealing ring is disposed in the first positioning hole; the second sealing ring is used to seal the gap between the ceramic tube and the inner wall of the first positioning hole.

7. The coating apparatus as claimed in claim 6, characterized in that, The second sealing mechanism includes: a second sealing plate, a sealing plate, a rear cover plate, and a second fastener; the second sealing plate covers and seals the second opening; the sealing plate is laid on the edge of the second sealing plate and the second opening; the rear cover plate covers the second sealing plate and is fixed to the base by the second fastener; the sealing plate is sandwiched between the edge of the second opening and the rear cover plate.

8. The coating apparatus as claimed in claim 7, characterized in that, Also includes: The third sealing ring; the second sealing plate has a second positioning hole for the other end of the ceramic tube to be inserted; the third sealing ring is disposed in the second positioning hole; the third sealing ring is used to seal the gap between the ceramic tube and the inner wall of the second positioning hole.

9. The coating apparatus as claimed in claim 8, characterized in that, The number of the first positioning hole, the protruding hole and the second positioning hole are each multiple; the number of the multiple first positioning holes, the multiple protruding holes and the multiple second positioning holes are each one-to-one.

10. The coating apparatus as claimed in claim 1, characterized in that, Also includes: A barometer; the barometer is used to detect the air pressure inside the chamber; The pressure gauge is mounted on the base.

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